Avoid fungus gnats

Just about anyone who grows houseplants has probably encountered fungus gnats -- a cloud of tiny, dark, delicate-bodied flies rises up from a plant when you disturb its leaves. While fungus gnats generally don't do much damage to plants, they are annoying. Allow the top couple inches of potting soil to dry out between waterings. Fungus gnat larvae need moisture to survive. Covering the surface of the growing mix with a thin layer of sand will also make it less enticing to females as a place to lay eggs.